Thiophene amines



Patented Jan. 13, 1953 THIOPHENE AMINES John W. Schick, Camden, andHoward D.

Hartough, Pitman, N. J., assignors to Socony- Vacuum Oil Company,Incorporated, a corporation cf New York No Drawing. Application October23, 1947, Serial No. 781,754

7 Claims. l The present invention relates to the condensationofsubstances having at least one hydrogen atom of pronounced activity andhydrohalides of ammonia and substituted ammonia by means of a highlyreactive aldehyde and; more particularly, to the condensation ofsubstances having at least one hydrogen atom of pronounced activity withhydrohalides of ammonia, alkyl substituted ammonia and hydroxylsubstituted ammonia by means of a highly reactive aldehyde in thepresence of an acid having an ionization constant above l 10- In anapplication for United States Letters Patent Serial No. 636,511, filedDecember 21, 1945, now abandoned, in favor of application Serial No.204,264, filed January 3, 1951, now U. S. Patent No. 2,612,505, HowardD. Hartough and Sigmund J. Lukasiewicz described the condensation ofthiophene and derivatives of thiophene having stable eiectropositivesubstituent groups attached to the thiophene nucleus with salts ofammonia, salts of monoand dialkyl substituted ammonia, salts of alkylpolyamines, aryl polyamines, urea and aniline in the presence offormaldehyde or its polymers. These investigators disclosed in theaforesaid application for United States Letters Patent that primaryamines, secondary amines and sub-resinous bodies of the nature of atertiary amine can be obtained. These investigators also showed that theproportion of each of these products in the final product can becontrolled by controlling the mole ratio of the reactants. For example,it was established that the amount of sub-resinous bodies in thereaction product can be kept at a minimum by using an excess ofthiophene and/or ammonium halide. It was also established that variationof the molar ratio of the reactants causes a variation in the molecularweight of the sub-resinous body as well as the proportion ofsub-resinous body to the primary and secondary amines in the reactionproduct. For example, when the reactants, thiophene, formaldehyde andammonium halide are reacted in the molar proportion of 1.2:lzl,respectively, the molecular weight of the benzene soluble subresinousbody is of the order of 637. When the molar proportion of thesereactants is 1:211 the molecular weight of the benzene solublesubresinous body is of the order of 1137.

It now has been found that substances capable of forming acids having anionization constant above 1 10- (Langes Handbook of Chemistry (5th ed.)pages 1397 and 1398) and acids having an ionization constant above 1 Xsuch as sulfurous acid in the form of acid sulfites, and aque- V 2 oussolutions of sulfur acid, benzoic acid, haloalkanoic acids, citric acid,formic acid, fumaric acid, phosphoric aid, maleic acid, etc., modify thepolymers obtained from the reaction of thiophene, formaldehyde andhydrohalides of ammonia, alkyl substituted ammonia, alkylene diaminessuch as ethylene diamine and the like, and hydroxyl substituted ammoniasuch as hydroxylamine in that the polymers are of lower molecular weightand of greatly improved color. In general, when one of the aforesaidmodifiers is added to the reaction mixture of thiophene or monoordi-substituted thiophene having at least one unsubstituted alphaposition, formaldehyde and ammonium halide or hydroxylamine halide andthe product neutralized, white resins or light colored viscous oils areobtained depending upon whether aqueous formaldehyde or a polymer offormaldehyde is used. This is in direct contrast to the resultsdescribed in the aforementioned Hartough and Lukasiewicz applicationSerial No. 636,511. Whereas Hartough and Lukasiewicz obtainedsub-resinous, viscous oils by reacting thiophene, ammonium chloride andaqueous formaldehyde in contra-distinction thereto when thiophene,ammonium chloride and aqueous formaldehyde are reacted in the presenceof an aforementioned modifier, resinous products are obtained ratherthan sub-resinous viscous oils. Similarly, whereas Hartough andLukasiewicz obtained resinous products when reacting thiophene, ammoniumchloride and a polymer of formaldehyde (parafcrmaldehyde), whenthiophene ammonium chloride and a polymer of formaldehyde(paraformaldehyde) are reacted in the presence of an aforementionedmodifier sub- -resinous viscous oils are obtained.

The products of the reaction in the presence of at least a molecularamount of alkali metal acid sulfite before neutralization arecrystalline and can be recrystallized from water as crystallinehydrates. The crystalline products readily dissolve in hydrochloric acidto free the anion of the modifier employed in the condensation reaction.When the condensation product produced in the presence of the [HSOs]group is heated in aqueous solution in the presence of an acid such ashydrochloric acid, sulfur dioxide is evolved. This latter reactionindicates decomposition of a product containing the anion of themodifier; in this instance, I-ISO3. Addition of sodium acetate or alkalito the aqueous solutions of the crystalline products frees the amineswhich are white thermoplastic resins partially soluble in benzene ordioxide, acetic acid, arsenic white thermoset resins wholly insoluble inbenzene.

P oducts having satisfactory colors were obtained when the ratio ofammonium halide to soluble bisulfite was as low as 5 moles of ammoniumchloride to one mole of sodium bisulfite. The upper limit of the molarratio appears to approach 1:1.

Indicative of the effect of modifiers of the aforesaid class. it is tobe noted that hard resins insolubl in benzene are obtained bv reactinone m le of thiophene. 3 moles of paraformaldehvde and one mole ofammonium chloride. In contra t to the foregoing results. the addition of0.2 to 0.4 mole of sodium bisulfite to the reaction mixture of one moleof thio hene, 3 moles of paraformalde yde and one mole of ammoniumchloride modifies the reaction and viscous oils soluble in benzene areobtained.

More highly polymerized material difiicultly soluble in benzene can beobtained by reacting the thio hene, formal ehyde and ammonium halide andintroducing the sodium bisulfit-e dropwise as a 40 per cent by weightaoueous solution. These more highly polymerized materials are of ood.color. 7

The foregoing can be generalized to provide the following description ofthe present invention. Thiophene and thiophene derivatives having atleast one unsubstituted nuclear hydrogen atom in the alpha position or,in general, substances having at least one hydrogen atom of pronouncedactivity, may be reacted with formaldehyde or its polymers and ammoniumhalides or hydroxylamine halides or hvdrohalides of alkyl substitutedammonia hydrohalides of alkylene diamines and the condensation modifiedby either adding the entire amount of the modifier to the initial reaction mixture or by slowly adding the modifier during the course of thereaction. The products of either operation are useful inmoisture-proofing fabric such as those comprised of wool, rayon, cottonand, in general. textile materials including paper, regeneratedcellulose, etc. They also may be used as fungicides and bactericidesparticularly when in combination with phenolic materials as describedhereinafter.

Illustrative, but not limiting, of the present invention are thefollowing examples.

Example I A mixture of about 84 parts by weight of thiophene (about onemole), about 100 parts by weight of 3'? per cent aqueous formaldehyde(about 1.2 moles), about 27 parts by weight of ammonium chloride( about0.5 mole) and about 52 parts by weight of sodium bisulfite( about 0.5mole), i. e. 1.0 mole equivalent of HSO3- or 0.5 mole sulfurous acid,was refluxed for about 5 hours. Upon cooling to ambient temperature acrystalline precipitate formed which, when separated and recrystallizedfrom hot water, gave a white crystalline product of the followinganalysis: sulfur, 18.6 per cent; nitrogen, 4.87 per cent.

A sample of crystalline material from a similar experiment after tworecrystallizations from water and drying was refluxed with benzene. Theamount of Water given off during the refluxing was abnormal and may havebeen due to the removal of water of hydration. The dried sample wasanalyzed and found to contain: sulfur, 21.5 per cent; nitrogen, 5.02 percent.

Example II A mixture of about 168 parts by weight of thiophene (about 2moles), about 180 parts by weight of paraformaldehyde (trioxymethylene)(about 6 moles), about 108 parts by weight of ammonium chloride (about 2moles) and about 20 parts by weight of acetic acid (depolymerizer of thetrioxymethylene) was heated to about '72 degrees centigrade for about 15minutes before a reaction set in. The addition of about 104 parts byWeight of sodium bisulfite (about one mole), i. e. about one molesulfurous acid in about 150 parts by weight of water (aqueous about 40per cent solution) was begun and the reaction temperature maintainedbelow about degrees centigrade by means of an ice bath. The addition ofthe aqueous solution of sodium bisulfite was completed in about one houradditional time. After neutralization with caustic soda, the product wasfound to be insoluble in cold benzene but soluble in boiling benzene.Removal of the benzene solvent yielded a thermoplastic resinous productof light red color. The thermoplastic material when analyzed had asulfur content of 24.1 per cent and a nitrogen content of 8.67 per cent.

The product obtained from the foregoing quantities of these materials inthe absence of sodium bisulfite was a deep yellow to red, brittle resininsoluble in benzene.

Examples III to VI trolled at 75 degrees centigrade by means of an icebath.

1 Included a small amount of benzene insoluble resin.

The products described in Table I analyzed as indicated:

I Percent Percent Hydroxyl Molecular Example Wt. s we N Number WeightExample VII A mixture consisting of about 420 parts by weight ofthiophene (about 5 moles), about 425 parts by weight of aqueousformaldehyde solution containing about 37 per cent formaldehyde (about 5moles), about 270 parts by weight of ammonium chloride (about 5 moles)and about 104 parts by weight of sodium bisulfite (about one mole), wasrefluxed for about 3 hours. The reaction mixture was then steamdistilled and 365 parts by weight of thiophene recovered. After cooling,the steam distilled reaction mixture was neutralized with about 6 molesof potassium hydroxide in the form of an aqueous 20 per cent p t ssiumhydroxide solution. The resulting mixture was steam distilled untilabout 500 parts by weight of distillate were collected. The distillatewas extracted with ethyl ether and about 23 parts by weight of a mixtureof Z-thenylamine and di-(2-thenyl)amine recovered from the extract. Upontreating the residue of the second steam distillation with benzene about203 parts by weight of sub-resinous amines were extracted by thebenzene. The benzene insoluble material I totalled about 80 parts byweight. The benzene insoluble material was dissolved in dilute hydrochloric acid, precipitated with caustic soda, waterwashed and dried. Thedried material was a light yellow resin.

Example VIII A mixture of about 756 parts by weight of thiophene (about9 moles), about 1225 parts by weight of an aqueous solution offormaldehyde containing about 37 per cent form-aldehyde (about 15moles), about 810 parts by weight of ammonium chloride (about 15 moles)and about 624 parts by weight of sodium bisulfite (about 6 moles) wasrefluxed for 4 hours at about 71 to about '72 degrees oentigrade.Crystals began to form after the reaction mixture had been stirred forabout 30 minutes. The reaction mixture was distilled and about 300 partsby weight of thiophene recovered. The residue was a pasty mass thatsolidified completely on cooling. Neutralization of a portion of theresidue of the reaction mixture produced a white flocculent resinousmass.

Example IX A portion of the residue from the reaction mixture describedin Example VIII and amounting to about 500 parts by weight wasneutralized with caustic and extracted with benzene. All of theneutralized mass, with the exception of about parts by weight, wassoluble in the benzene. The benzene-insoluble material was plastic. andcould be thermoset to a hard white resin by boiling with water. Thebenzene-insoluble material had a nitrogen content of 18.55 percent and asulfur content of 20.9 per cent.

The benzene-soluble portion was distilled and about 9 parts by weight of2-thenylamine and about 3 parts by weight of di-(2theny1)amine wereobtained. About 69 parts by weightwere Example X A portion of theresidue of the reaction mixture obtained in Example VIII totalling about500 parts by weight was neutralized with an excess of caustic soda andabout parts by weight of an aqueous solution containing about 37 percent formaldehyde were added. A heat of reaction and slow solidificationof the oily material was observed. After stirring the mixture for aboutan hour the resinous material formed into a white mass that had some ofthe properties of an elastomer. The material was water-washed andbenzene added. The material was insoluble in benzene and an extremelystable emulsion of water, benzene and the resinous amine was formed. Theemulsion was broken by removing the benzene by evaporation. The ben-Zens-insoluble material analyzed 6.77 per cent nitrogen and 16.4 percent sulfur.

Example XI A mixture containing about 756 parts by weight of thiophene(about 9 moles), about 810 parts by weight of ammonium chloride (about15 moles) and about 312 parts by weight of sodium bisulfite (about 3moles) was prepared and about 1215 parts by weight of an aqueoussolution containing about 36 per cent formaldehyde (about 15 moles)added thereto. The reaction mixture was refluxed at 68 to 70 degreescentigrade for about 2 hours and then distilled. About 370 parts byweight of thiophene and dimethylformal [(ornoncrn] were removed asdistillate. The still residue was neutralized with caustic soda andsteam distilled until about 2000 parts by weight of distillate wereobtained. The distillate was saturated with common salt (NaCl) andextracted with ethyl ether whereby about 55 parts by weight of a mixtureof 2-thenylamine and di- (2-thenyl)amine was obtained. The residue ofthe steam distillation totalled about 800 parts by weight and was alight yellow, thermoplastic, benzene-insoluble resin which had anitrogen content of 8.6 per cent and a sulfur content of 20.9 per cent.

The analyses indicate that sulfur andv nitrogen are present in roughlythe same atomic proportions, e. g. one atom of nitrogen per atom ofsulfur or per thiophene radical. Assuming that Z-thenylformaldimine,

A H HE E H H y can. F S shel 8 ll llllL Itttl Ill 72 where n is a smallinteger.

There is evidence that both types of polymerization occur. Thus, whenN-(fi-methyl-Z- thenyDformaldimine, i. e. a compound in which the otheralpha position of the thiophene radical is blocked, is polymerized withaqueous hydrochloric acid, in the manner described hereinafter, aresinous polymer is obtained.

N-(-methyl-2-thenyl) formaldimine was polymerized by mixing 45.5 partsby weight of the formaldimine, 950 parts by weight of water and about235 parts by weight of concentrated hydrochloric acid and boiling themixture until a dark, reddish oil separated. This oil appeared to be acomplex hydrochloride of some polymer since it was soluble in alcohol orwater. Neutralization of the oil with aqueous caustic yielded a yellowresinous product which was not soluble in common solvents such asacetone and benzene. The yellowish resin can be construed to be apolymer of the original N-(5-methyl-2-thenyl)formaldimine polymerizedthrough the formaldimine grouping. Such a polymer can be represented bythe following formula:

H H H a S Nli N. i N H I l i i Hrs i all.

CH3 1?. CH:

Consequently, when the other alpha position of the thiophene radical isnot blocked as in N-(2- thenyhformaldimine, polymerization may takeplace either through the other alpha position of the thiophene radicalor through the formaldimine grouping or through both.

Treatment of materials having structures which may be represented byeither formula A or formula B with formaldehyde causes further'resinification to products which may be represented by formulae A1 andBi respectively,

H-G-H I l or by several other cross linkage patterns. Treatment of amolecule of the illustrated type with dilute acids should break down themethylene bridges in a manner similar to that which takes place in thedecomposition of hexamethylene tetramine to formaldehyde and ammoniumchloride in the presence of hydrochloric acid. When theformaldehyde-treated neutralized resinous products produced in thepresence of sodium bisulfite are dissolved in dilute hydrochloric acidcopious amounts of formaldehyde are given off.

The resinous polymers made from thiophene, paraformaldehyde and ammoniumhalide described in copending application Serial No. 636,511 appear tofunction similarly but are more brittle and do not have the plasticproperties of the materials obtained from condensation of thiophene andammonium halide in the presence of aqueous formaldehyde and sodiumbisulfite. Furthermore, in the aforesaid application the use of anexcess of aqueous formaldehyde was shown to give subresinous oils Whilethe use of paraformaldehyde resulted only in resins. On the other hand,modification of the condensation by the use of sodium bisulfite or othermodifiers as defined hereinbefore results in a reversal of the physicalform of the condensation products That is to say, aqueous formaldehydeand bisulfite produce resinous products instead of subresinous productswhile paraformaldehyde and bisulfite produce subresinous productsinstead of resinous products.

Advantage can be taken of the presence of loosely bound formaldehyde inthe products and the condensation product blended with phenol-aldehydetype resins to cure the phenolic type resin and to impart new propertiesto the finished Bakelites.

It has also been found that water-soluble resinous materials as thehydrohalide can be obtained when phenol is substituted for say up to 25per cent of the thiophene in the reaction mixture. At about 50 per centproportions water-insoluble products result and it is difiicult topredict a co-reaction.

In general, thiophene or monoor di-substituted thiophenes having atleast one unsubstituted alpha position in which the substituent groupsare stable electropositive groups may be reacted with ammonium halide inthe presence of an acid having an ionization constant above 1X10- saysulfurous acid, to produce linear thenylamine polymers which havehydrogen atoms capable of reacting in alkaline media with furtheramounts of formaldehyde.

While applicants have no definite proof of the existence of materialshaving compositions corresponding to the foregoing formulae and whilethey do not wish to be limited by any theories based thereon, thepresence of structures analogous thereto will explain some of theproperties of the materials obtained by condensing thiophene, ammoniumhalide and formaldehyde in the presence of a modifier of the classdefined hereinbefore, for example sodium bisulfite.

l. A sulfite or corresponding salt of the amine is formed having acomposition which may be represented by the formula R-CHzNH-SO3M inwhich R is thiophene and M is a metal or hydrogen.

2. When M is a hydrogen a zwi-tter ion" re sults to produce a productwhich may be represented by the formula RCH2N+H2CH2SO3' Where R. has thesame significance as before.

This compound is produced in the following manner: about 4.20 parts byweight of thiophene- (about 5 moles), about 810 parts by Weight of anaqueous 36 per cent formalin solution (about moles) and about 270 partsby weight of am monium chloride (about 5 moles) were maintained at about24 to 27 degrees centigrade while passing gaseous sulfur dioxide throughthe mixture at approximately 400 millimeters per minute. After about onehour, a crystalline material began to form. Fifteen minutes later, thereaction mixture was nearly solid. The mixture was filtered and a whitecrystalline product obtained. Neutralization of the aqueous filtratewith caustic soda yielded per cent of 2-thenylamine and 34 per centN-(2-thenyl)formaldimine having a boiling point at a pressure of 3.7millimeters of mercury of 100 to 121 degrees centigrade, n above 1.595.The crystalline product when recrystallized from water and alcohol,melted at 135 to 136 degrees centigrade and had a neutral equivalent of216. When this compound was treated with hot aqueous hydrochloric acid,sulfur dioxide was evolved. When sulfur dioxide was bubbled through asample of authentic N-(Z-thenyl)formaldimine (C4H3SCH2N'=CH2) a whitecrystalline product was obtained having the same melting point (135 to136 degrees centigrade). A mixed melting point gave no depression. It isbelieved the product is (neutral equivalent=206). The aqueous reactionlayer was neutralized with caustic soda and a white solid material (210parts by weight) was obtained. When heated above 200 degrees centigradethis material did not melt but turned yellow.

The following examples are illustrative of the use of other materialshaving at least one hydrogen atom of pronounced reactivity in the placeof thiophene in the reaction discussed hereinbefore.

Example XII About 98 parts by weight (about one mole) ofS-methyl-thiophene, about 54 parts by weight of ammonium chloride (aboutone mole) and about 53 parts by weight of sodium bisulfite (about 0.5mole) were mixed. To the mixture were added about 162 parts by weight ofan aqueous solution containing about 36 per cent formaldehyde (about 2moles of formaldehyde). The reaction mixture was heated to about 76degrees centigrade and the reaction temperature maintained at about 74to 77 degrees centigrade for about one hour. The resultant orangecolored solution stratified upon standing at airibient temperatures.Neutralization of a portion of this material with caustic soda gave alight-pink resin. This material imparted water repellency to textilefabrics.

Example XIII About 84. parts by weight of thiophene (about one mole),about 104 parts by weight of sodium bisulfite (about one mole), about 49parts by weight of ammonium chloride (about 0.9 mole) and about 28 partsby weight of octadecylamine (about 0.1 mole) were mixed and treated withabout 10 parts by weight of concentrated hydrochloric acid to convertthe octadecylamine to the amine hydrochloride. About 162 parts by weightof aqueous 36 per cent formalin solution (about 2 moles) were added tothe foregoing mixture and the entire mixture heated at the refluxtemperature (about 68 to 70 degrees centigrade) for one hour. Thereaction mixture, upon cooling, crystallized to a white semi-solid mass.Neutralization of the reaction mixture with caustic soda produced awhite thermoplastic resin.

ramble XIV About 84 parts by weight of thiophene (about one mole), about131 parts by weight of ethylenediamine dihydrochloride (about one mole),about 162 parts by weight of an aqueous 36 per cent formalin solution(about 2 moles of formaldehyde) and about 100 parts by Weight of sodiumsulfite (about one mole) were mixed and heated at the reflux temperature(about 68 to 74 degrees centigrade) for about 4.5 minutes. The resultantreacted mixture was semi-solid and practically white in color.Neutralization of a portion thereof with caustic soda produced a whiteflocculent resin. This is in contrast to the resin obtained as describedin copending application Serial No. 727,300, new U. S. Patent 2,585,652,issued November 20, 1951, which was a brown brittle product.

Example XV About 98 parts by weight of cyclohexanone (about one mole),about 54 parts by weight of ammonium chloride (about one mole) and about104 parts by weight of sodium bisulfite (about one mole) were mixed.About 162 parts by weight of an aqueous 36 per cent formalin solution(about 2 moles) were added very slowly (dropwise) to the aforesaidmixture. A heat of reaction developed during the addition of theformalin solution and the temperature of the reaction mixture rose toabout 52 degrees centigrade. After the temperature began to fall thereaction mixture was heated at about 90 to 97 degrees centigrade forabout 2.5 hours. The resultant solution had a pink fluorescent color.Neutral ization of a portion of the aqueous mixture produced alight-pink thermoplastic, pliable resin. This is in distinct contrast tothe resin prepared in the absence of sodium bisulfite. In the absence ofsodium bisulfite the reaction was very difficult to control, i. e. thetemperature rose to about 105 degrees centigrade before subsiding, thereaction mixture was a deep brown color and a brittle, hard, thermosetresin Was obtained by neutralization with caustic soda.

Example XVI About 43 parts by weight of tertiary butyl-3- thienylthioether,

(about 0.25 mole) about 14 parts by weight of ammonium chloride (about0.25 mole) and about 26 parts by weight of sodium bisulfite (about 0.25mole) were mixed. About 81 parts by weight of aqueous 36 per centformalin solution (about one mole of formaldehyde) were added. Thereaction mixture was refluxed at about to degrees centigrade for about 8hours. A portion of the material reacted. The reddish colored aqueouslayer on neutralization gave a light brown resin capable of impartingthe property of water-repellency to textile fabrics.

Example XVII About one mole of pyrrole was treated with about 2 moles ofammonium chloride, about one mole of sodium bisulfite and about 3 molesof 36 per cent formaldehyde solution. The temperature rose to 70 degreescentigrade, and was controlled there by means of an ice bath. Thereaction mixture was stirred for about one hour. Most of the reactionmixture was soluble in hot water.

Example XVIII Example XIX About 234 parts by weight of thiophene (about2.5 moles) and about 46 parts by weight of phenol (about 0.5 mole) weremixed. About 266 parts by weight of ammonium chloride (about 4 moles),about 80 parts by weight of sodiumbisulfite (about 0.8 mole) and about750 parts by weight of an aqueous 36 per cent formalin solution (about 9moles of formaldehyde) were added to the mixture of thiophene andphenol. The final mixture was heated at reflux for about 2 hours. Theresultant reacted mixture was a light-red color which uponneutralization with caustic soda produced a light-brown resin capable ofimparting water-repellency to textile fabrics.

Example XX About 94 parts by weight of phenol (about one mole), about 54parts by weight of ammonium. chloride (about one mole), about 104 partsby weight of sodium bisulfite (about one mole), and about 243 parts byweight of an aqueous 36 per cent formalin solution (about 3 moles) weremixed. The reaction mixture was maintained at about 85 to 90 degreescentigrade for about 6 hours. After the first few minutes it wasmanifest that the phenol was reacting and that the mixture was becomingthicker as the reaction progressed. A whitish-yellow layer formed thatwas practically insoluble in water. This product contained about 4.43per cent nitrogen.

The use of sulfur dioxide in the place of sulfites of the metals, suchas sodium bisulfite, provides a more flexible procedure. Thus, when thereaction is carried out at about 25 degrees centigrade a whitecrystalline product identified as was obtained in good yield. Thiscompound appears to be the basic compound in all of the reactions atdifferent temperatures; however, as the reaction temperature is raisedappreciably above 25 degrees centigrade other reactions take place anddifferent products are obtained. Neutralization of the filtrate withcaustic sodayields' Z-thenylamine and N-(2-thenyl)formaldimine.

At 35 degrees centigrade a good'yield (62 per cent) of N- (Z-thenyl)formaldimine was obtained. At 45 degrees centigrade a lower yield ofN-(Z-thenyDformaldimine was obtained and at 55 degrees centigradedi-(2-thenyl) amine (C4I-I3SCH2) zNl-I was obtained but no N-(Z-thenyDformaldimine could be isolated. Above 55 degrees centigradeanother reaction occurs in which a fair yield (24 to 32 per cent) ofthenylamine is obtained together with some di- (2- thenyl) amine,

Illustrative, but not limiting, of the reaction employing thiophene or aderivative of thiophene with at least one unsubstituted alpha nuclearposition are the following examples.

Example XXI About 420 parts by weight of thiophene (about 5 moles),about 810 parts by weight of an aqueous 36 per cent formalin solution(about 10 moles) and about 270 parts by weight of ammonium chloride(about 5 moles) were maintained at about 24 to 27 degrees centigradewhile passing gaseous sulfur dioxide through the mixture atapproximately 400 millimeters per minute. After about one hour, acrystalline material began to form. Fifteen minutes later, the reactionmixture was nearly solid. The mixture was filtered and a whitecrystalline product obtained. Neutralization of the aqueous filtratewith caustic soda yielded 15 per cent of 2-thenylamine and 34 per centN-(2-thenyl)formaldimine having a boiling point at a pressure of 3.7millimeters of mercury of to 121 degrees centigrade, n above 1.595. Thecrystalline product when recrystallized from water and alcohol, meltedat to 136 degrees centigrade and had a neutral equivalent of 216. Whenthis compound was treated with hot aqueous hydrochloric acid, sulfurdioxide was evolved. When sulfur dioxide was bubbled through an aqueoussolution at room temperature, said solution containing authentic N (2-thenyl) formaldimine a white crystalline product was obtained havingthe same melting point (135 to 136 degrees centigrade). A mixed meltingpoint gave no depression. It is believed the product is (neutralequivalent=206) The aqueous reaction layer was neutralized with causticsoda and a white solid material (210 parts by weight) was obtained. Whenheated above 200 degrees centigrade this material did not melt butturned yellow.

Example XXII About 340 parts by weight of thiophene (about 10 moles),about 1620 parts by weight of an aqueous 36 per cent formalin solution(about 20 moles of formaldehyde) and about 540 parts by weight ofammonium chloride (about 10 moles) were mixed and maintained at about 35degrees centigrade, while passing gaseous sulfur dioxide therethrough ata rate of about 400 milliliters per minute. After about 2.5 hours all ofthe thiophene appeared to have reacted. The crystalline product (135parts by weight) was separated and the yellow aqueous solutionneutralized with caustic soda and extracted with benzene. The benzenewas removed and the residue distilled at sub-atmospheric pressure. About469 parts by weight of distillable product, boiling point 114 degreescentigrade at a pressure of 4.5 millimeters of mercury to 146 degreescentigrade at a pressure of 2 millimeters of mercury were obtained. Amajor portion of this product is N-thenylformaldimine containing 25.8per cent sulfur. [Calculated for C4H3SCH2N:CH2) 25.6 per cent sulfur] Ina repetition of the foregoing, 782 parts by weight of benzene solublematerial was obtained. This material was fractionated under reducedpressure into 5 distillates or cuts and a residue with the followingresults:

Pot Vapor Mm.

out Temp. Temp. Press.

165 90 4. 8 170 114 4. 5 7 1. 5869 178 109 2. 8 59 l. 6073 195 119 2.0138 1. 6144 210 135 2. 147 1. 6160 220 146 2.0 118 l. 6162 Residue 245Total 756 Analyses Per- Per- Approx. 7

cent N cent S N to S Ratio Cut 3 9.53 25. 83 1:1 Cutfl .1 9. 72 26. 011:1 Residue 9. 90 Composition before disti tio 10. 35 24. 22 1:1

Although the major portion of this material isN-(z-thenyl)-formaldimine, oxidation of cut 5 with potassiumpermanganate in alkaline solution yields 2,5-thiophene dicarboxylicacid, indicative that a compound having the formula is present indeterminable amounts.

Example XXIII About 84 parts by weight of thiophene (about one mole),about 162 parts by weight of aqueous 36 per cent formaldehyde solution(about 2 moles) and about 54 parts by weight of ammonium chloride weremaintained at about 45 degrees centigrade while introducing gaseoussulfur dioxide at a rate such that the temperature of the reaction wasmaintained at about 45 degrees centigrade without toomuch difiiculty.After about 3 hours, the reaction mixture was yellow in color. Unreactedthiophene was separated from the aqueous layer and about 21 parts byweight of thiophene were recovered. The aqueous layer was neutralizedwith caustic soda and extracted with benzene. The benzene was removed bydistillation and the residue was distilled under reduced pressure. About23 parts by weight of a distillable product was obtained. The distillatehad a boiling range of 105 to 125 degrees centigrade at 1.5 millimetersof mercury. The product was N-thenylformaldimine.

Example XXIV About 84 parts by weight of thiophene (about one mole),about 162 parts by weight of an aqueous 36 per cent formaldehydesolution (about 2 moles) and about 54 parts by weight of ammoniumchloride (about one mole) were maintained at about 55 degreescentigrade, while in- 14 troducing gaseous sulfur dioxide at a rate suchthat no great diificulty was encountered in maintaining the temperatureof the reaction mixture at about 55 degrees centigrade. After about 3hours the solution was light orange in color. About 22 parts by weightof unreacted thiophene were separated from the aqueous layer. The

aqueous layer was neutralized with caustic soda and extracted withbenzene. The benzene was removed and the residue distilled under reducedpressure whereby about 28 parts by weight of distillable product wasrecovered. Of the foregoing product, about 25 parts by weight were di-(2-theny1) amine having a boiling range of 155 to 168 degrees centigradeat 3 millimeters of mercury.

Example XXV About 84 parts by weight of thiophene (about one mole),about 162 parts by weight of an aqueous 36 per cent formaldehydesolution (about 2 moles) and about 54 parts by weight of ammoniumchloride (about one mole) were maintained at about 65 degrees centigradewhile introducing gaseous sulfur dioxide at a rate which did not makemaintenance of the temperature too difficult. After about 3 hours thereaction mixture was orange in color. About one gram of unreactedthiophene was separated from the aqueous layer. The aqueous layer wasneutralized with caustic soda (any other suitable alkaline materialcould have bee-n used) and the neutralized mixture extracted withbenzene. The benzene was removed and the residue was disstilled underreduced pressure. About 33 parts by weight of distillable products wererecovered. The distillate had a boiling range of 43 to 143 degreescentigrade at a pressure of 1 to 2 millimeters; about 60 per cent of thedistillate was 2- Example XXVI About 210 parts by weight of thiophene(about 2.5 moles), about '162 par-ts by weight of an aqueous 36 per centformaldehyde solution (about 2 moles) and about 162 parts by weight ofammonium chloride (about 3 moles) were heated to reflux and gaseoussulfur dioxide introduced at a rate of about 400 milliliters per minute.After about one hour about parts by weight of unreacted thiophene wereremoved by steam distillation and the residual aqueous solutionneutralized with caustic soda and extracted with benzene. The benzenewas removed and the residue distilled under reduced pressure. About 52parts by weight of a distillable product having a boiling range of 47 to143 degrees centigrade at 2 to 3 millimeters of mercury were recovered.About 61.5 per cent of the distillate was Z-thenylamine H C NH2 s HExample XXVII A mixture of about 84 parts by weight of thiophone (aboutone mole) about 162 parts by weight of an aqueous 36 per centformaldehyde solution (about 2 moles), about 54 parts by weight ofammonium chloride (about one mole) and about 115 parts by weight of 85per cent orthophosphoric acid (about one mole) were warmed at 35 degreescentigrade for about 3.5 hours. From gross observations the reactionproceeded in all respects similarly to the sulfur dioxide reactionsdescribed hereinbefore and was worked up in a similar manner.Distillation of the benzene-soluble amine yielded '23 parts by weight ofN-(Z-thenyDformaldimine boiling point 123 degrees centigrade at apressure of 2 millimeters of mercury and about 46 parts by weight ofpolymerized residue.

Phosphoric acid yields a crystalline addition product withN-(Z-thenyl)formaldimine similar to the addition product obtained withsulfurous acid.

' Example XXVIII About 168 parts by weight of thiophene (about 2 moles),about '70 parts by weight of hydroxylamine (about one mole), and about104 parts by weight of sodium bisulfite (about one mole) were mixed.About 162 parts by weight of an aqueous 36 per cent formaldehydesolution (about 2 moles) were added to the mixture thu formed withexternal cooling. The temperature of the mixture rose to about 50degrees centigrade in spite of the external cooling. After the heat ofreaction had subsided, the mixture was warmedto about '72 degreescentigrade at which temperature reflux again became vigorous. Afterrefluxing subsided (which required about to minutes), the pale yellowsolution was cooled, diluted with water to a working solution anddeposited on cotton poplin to produce a water-proofed textile.

It will be manifest to those skilled in the art that the foregoing is adetailed description of the reaction between materials having at leastone hydrogen atom of pronounced activity, formaldehyde and a hydrohalideof ammonia or alkyl or hydroxyl substituted ammonia in the presence ofacids having ionization constants above 1 l0- such as acetic acid,arsenic acid, benzoic acid, haloalkanoic acids, citric acid, formicacid, fumaric acid, maleic acid, and sulfurous acid.

We claim:

1. A method for producing N-(2-thenyl)formaldimine, Z-thenylamine and asulfurous acid addition compound of N-(Z-thenyDformaldimine whichcomprises mixing thiophene, aqueous formaldehyde and ammonium chloridein the molar proportion of 1:211 and passing aqueous sulfur dioxide intothe mixture whilst maintaining a temperature of about degrees Centigradeuntil at least crystalline material begins to form, separating thecrystalline material from the reaction mixture, and neutralizing theaqueous filtrate with caustic oda, whereby is obtained as thecrystalline product and N-(2- thenyhformaldimine and Z-thenylamine areobtained from the aqueous liquors.

2. A method for producing N- (Z-thenyl) formaldimine which comprisesmixing thiophene, aqueous formaldehyde and ammonium chloride in theproportion of 1:2:1 and passing gaseous sulfur dioxide through themixture whilst maintaining a temperature of about 35 to about 45 degreescentigrade until a crystalline product is produced, separating thecrystalline product from the aqueous solution, neutralizing the aqueoussolution, extracting the neutralized aqueous solution with an organicsolvent for N- (2-thenyl) formaldimine, fractionating the extract toobtain a distillate having a boiling range of 114 degrees centigrade ata pressure of 4.5 millimeters of mercury to 146 degrees centigrade at apressure of 2 millimeters of mercury containing N-(Z-thenyDformaldimine.

3. A method of producing di-(Z-thenyl) amine which comprises reacting at55 degrees centigrade thiophene, ammonium halide, formaldehyde and anacid having an ionization constant above 1 10- but not greater thanabout 1.7 10- and recovering di-(2-thenyl)amine.

4. A method of producing thenylamine which comprises reacting at above55 degree centigrade to the reflux temperature, thiophene, ammoniumhalide, formaldehyde and an acid having an ionization constant above 110- but not greater than about 1.7 10- and separating thenylamine.

5. The method described and set forth in claim 4 in which the acidshaving an ionization constant above 1 10- but not greater than about1.7x 10- is sulfurous acid.

6. The method described and set forth in claim 3 and in which the acidhaving an ionization constant above 1X10" but not greater than about 1.710 is sulfurous acid.

7. As a new product, a compound having a structure conforming to theformula 4- S CHzNHzCHzSOshaving a melting point of to 136 degreescentigrade and evolving sulfur dioxide when treated with hot aqueoushydrochloric acid.

JOHN W. SCHICK. HOWARD D. HARTOUGH.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS I Number Name Date 2,453,085 Caesar Nov. 2, 19482,453,086 Caesar Nov. 2, 1948 FOREIGN PATENTS Number Country Date 51,629Netherlands Dec. 15, 1941 OTHER REFERENCES Hartough, J. Am. Chem. 800.,70, 4013 (1948).

1. A METHOD FOR PRODUCING N-(2-THENYL) FORMALDIMINE, 2-THENYLAMINE AND ASULFUROUS ACID ADDITION COMPOUND OF N-(2-THENYL) FORMALDIMINE WHICHCOMPRISES MIXING THIOPHENE, AQUEOUS FORMALDEHYDE AND AMMONIUM CHLORIDEIN THE MOLAR PROPORTION OF 1:2:1 AND PASSING AQUEOUS SULFUR DIOXIDE INTOTHE MIXTURE WHILST MAINTAINING A TEMPERATURE OF ABOUT 25 DEGREESCENTIGRADE UNTIL AT LEAST CRYSTALLINE MATERIAL BEGINS TO FORM,SEPARATING THE CRYSTALLINE MATERIAL FROM THE REACTION MIXTURE, ANDNEUTRALIZING THE AQUEOUS FILTRATE WITH CAUSTIC SODA, WHEREBY